Hi, I’ve been doing some cutting with my MPCNC machine and reasonable success with soft materials, working up to something harder.
I’ve been testing some different CAM packages and in testing with MeshCAM I found an issue with losing steps on the Z axis. MeshCAM does a LOT of Z axis moves during the milling operations.
I’ve tested with the torture test gcode for the Z Axis and it does appear that I lose some steps. I’ve checked free movement of the Z Axis and loosened a couple of bolts a bit, and pushed the current limit back up towards .6V ref from .49V. But there is still some lost steps especially when I try to machine something more substantial then foam. It’s not much but it is enough to be a problem if I was machining a real part.
I’ve made sure the threaded rod isn’t rubbing, things seem to move pretty easy. X and Y are fine so far, just the Z is problematic. Didn’t see this until I added the DeWalt router.
I had some older steppers that I used in the initial build, but going back and looking at the specs for those steppers and the ones in the link from the parts page here it appears that the holding torque for my steppers is 47 oz-in and the ones on Amazon are 84 oz-in. The current rating on my steppers is .8 Amp per winding.
So I’m thinking that I probably need to get the beefier steppers and change out at least the Z axis stepper to correct the problem, unless anyone has other suggestions. I’ve pretty much exhausted addressing the usual suspects.